Lathe.



PATENTED AUG. 6, 1907.

H. BERTRAM.

LATHE.

APPLICATION I'ILBD MAR. 11. 190?.-

- bearing: fl, the arbor journaled as usual in these two HENRY summit, or

LATHE.

snares earner DUNDAS,,ONTARIO, CANADA, ASSIGNOR roJrrrn-ioi-rn BERTRAM sons enemy, no, or nuxnisooininn Specification of Letters Patent.

iatented 6,. Ill-30?.

Application filed March 11,1907. Serial No. 361,775

To all whom it may concern:

Be it known that 1,.HENRY BER'rnAn, a subject of Gr'eapBritain, residing in Dundas, Ontario, Canada, have invented certain new and useful Improvements in Lathes, of which the following is a specification. 7

Under modern conditions of lathe use, in which remarkably heavy cuts are taken with the recently developed high speed steels, there has developed a tendency for the lathe arbor to spring into a deflection between its bearings. With extra heavy work being done at the face plate, either boring or turning, the tendency is for the nose of the arbor to,spring upwardly and deflect the central portions of the arbor, between its bearings, downwardly.

My present invention aims to so stiffen the arbor as to lessen the evil referred to.

My improvements will be readily understood from the following description taken in connection with the accompanying drawing in which:

Figure 1 is a front elevation of the headstock of lathe exemplifying my invention: Fig. 2 a vertical longitudinal section of the same: and Fig. 3 a rear end elevation of the head-stock, part vertical transverse section.

In the drawing:l, indicates the head-stock: 2, the front arbor bearing supported thereby: 3, the rear arbor bearings: 5, the usual face gear fast on the arbor between the two bearings and just beside the front bearing: 6, the bearing-cap for the front bearing: 7, the

bearing-cap for the rear bearing, none of the parts thus far referred to being necessarily different from what is usual in latheconstruction: 8, a stout sleeve encircling the arbor" between the face gear and the rear bearing, its bore being considerably larger than the portion of the arbor encircled by the sleeve? 9, a lining, preferably of soft metal, as Babbitt metal, tightly fitting the bore of the sleeve, the bore of this lining having a snug running fit upon the portion of the arbor surrounded by the sleeve: 10, a bearing carried bythe head-stock between the two arbor-bearings, this" bearing being engaged by the periphery of the sleeve near "its front end: 11, a similar bearing carried by the headstock and engaging the periphery of the sleeve near its rear end; 12, a bearing-cap for the bearing 10: 13, the bearing-cap for the bearing 11, the cap 12 being preferably formed integrally with the cap 6, and the cap 13 intogrally with cap 7: 14, a driving'device fast upon the sleeve between the two sleeve bearings, which. driving device may be either a gear or pulley, the latter being shown in the illustration: 1:), a pinion fast with the rear end of the sleeve: 16, gear fast on the front nd of. the sleeve between the frontsleevo bearing and the face gear fast. on the arbor: 17, clutch-mechanism carried by the face gear and adapted to serve in lockingthat gear to gear 16 when it is desired thatthe sleeve 1 toward downward deflection. This stiifening effect clutch 17 be thrown so as to lock gears l6 and 5 together and arbor turn together: 18, mechanism for tl'irowi this chm-111.19, a baclcsgcar shaft journaled in the head-stock parallel with the arbor and adapted for endwise movement: 20, a baekgear sleeve splined on the baelrgear shaft: 2], a gear "'ied by this sleeve and adapted to engage p on of the arhonslem 22, a gear fast on the bac.-.gear sleeve and adapted to engage gear 16 of the arbor sleeve: 23, a handle shifting the haclzgcar sleeve endwise on the shaft, this handle being illustrated as provided with a gear section engaging a rack formed on the hack gear sleeve: 2- 3, =31 shifting device for moving the baekgear shaft endwise, this device being illustrated pinion engaging a rack on a sliding block forming one of the bearings oi the bacligcar shaft: 25, a housing connecting the cap of the front sleeve bearing with the cap of the front arbor-bearing and so expanded as to make room for gears 5 and lo: and 26, a pinion fast on the backgear shaftand adapted to engage far: ear 5.

As to the general motion effect? due to the error merit of gearing little need be said. When power applied by belt to pulley l4 and the gearing is in condition illustrated, then the power is transmitted to the arbor through gears 16, 22, 26 and 5, and the arbor iuns slower than the pulley, the sleeve turning freely on the arbor. If the la'clrgear sleeve be shifted to the left so as to disengage gears 16 and 22 from each other. and engage gears 15 and 21 with each other then the power will be transmitted from the pulley to the arbor through gears 15, 21, 26 and 5, and the arbor will turn much slower than in the former case. If the'backgear sleeve be shifted to theleit i-"ar enough to disengage 15 and 21 witlreach other then the-backgea-rs beconie idle and the pulley sleeve would turn freely and idly upon the arbor without turning the latter. lint i then the pulley sleeve becomes locked to the arbor; the arbor will turn at the'same rate as the pulley, and. under these conditions, in order-to lessen friction, the backgear shaft may be shifted to the right so as to disengage pinion 26 from gear. 5 and permit the baclrgear shaft to remain at rest.

When the lathe is doing its heavies worlr, as .repre sented by the slower speeds of the arbor, then the nor, mal tendency of the lathe arbor would be to defiecv downwardly between its two end beaii-ings'this f tion being brought about by the upward strain of cutting tool, strain impos d upon the f 't p when at like, with the front arbor-bearing a fulcrum. 1hr;

ding sleeve 8, snugly fitting the gene interport-ion of the arbor, serves of itself is eatly stiffenthe arbor at these portions otherwise tending of the snugly fitting sleeve being in a measure indel tlt)\\'ll\'f;tl' l deflection of the sleeve and arbor.

pendent of the sleeve bearings and ot' the pulley and 1 lining El within the sleeve is distinctly advantageous in would in considerable degree he realized it the sleeve were without external bearings of its own and if the poweuwas applied to the arbor by other means than through the sleeve. But, notwithstanding this stiffening et'l'eet of the sleeve upon the arbor, the sleeve itself is susceptible of some yielding defleet iuuand therefore any supporting'hearing underneath the sleeve would be lllfllll'ttfll) advantageous. The two sleeve bearings 10' and 1]. have this effect of supporting the sleeve against downward deflection. and this supporting efleet would he realized to considerable degree it the sleeve was supported by but a single bearing. Again, regardless of the supporting effeet gi'xen to the structure bythe sleeve -l earings. the upward strain of the driving belt upon the pulley serves in a measure in resisting the permittingof sueh reparation as is neeessary to maintain the snttg'tiess ot' fitting uponthe uthm' \Vllitll is. essential in realizing the results aimed at.

l elaitnt-- ln a lathe. the ttlllllillltll'llltl. substantially as set forth. of a head-smelt. a front at'lmr hearing and :1 rear :tt'hor hearing (.llllt'tl thereby. an at'hor jonrnaleti in the flllltW- hearings. a sleeve sin-rounding and snugly titling: the nrhtn' between the two arlmr-lrearinyas and adapted to turn thereon, and n heat'ing-support t'nrried by the head-stock het\\'een the arlmr-heat-ings and eng sing helow the sleeve and serving'to resist the dmvnwaitl tlextn-tof the arhm' and sleeve.

' HENRY lll'llt'lltAM, Witnesses l'htx .'l (l. Mammy. llltllaltll Ptt'rtit-tn. 

